That is basically what insurance is, a risk management pool. If a company has to pay out a bunch of claims, they are going to recoup it from those whose risk they manage.
I have been with Erie for 18 years and price shop every two years. Only one time was I able to beat their rates (truly comparing apples to apples.) That was with Liberty Mutual (through my College Alumni Association) and that would have saved me $50./year on home and auto combined.
Two years ago, I went to a State Farm agent to get a quote. Once I told him that I was with Erie, he said that he would be glad to give me a quote but there was no way he could beat their rates. After about ten minutes of conversation, he admitted that he carried his own personal policies through Erie.